Bellhop: No more than 5€, about 1€ per bag.
House Cleaning: 1€ per night if anything.
Barber / hair dresser: Depending on the price of the service required you may decide to round-up the bill. Up to 5 euros if the service was exceptional
Stylist: Same as above. Up to 5€ if the experience was amazing
Tour guides: If the tour was free, the guide makes his or her money on tips so make sure to give something. This is expected. The tip will need to be thought on a per person basis. A normal tip would be 3-5€ and up to 10€ for a exceptional guide (we recommend you bear in mind the overall amount of people in the tour. Less people normally imply higher tip.
On paid group tours people don’t usually leave a tip. If anything, 1€ or 2€.
If it was a private tour you don’t have to give a tip. However, guests develop a bit of a relationship with guides after spending the day with them and tend to leave a bit more that in other situations. Up to ten % of the cost of the tour.
Spa Service Provider: A tip isn’t expected, but you can leave up to 10 percent for anything that goes above and beyond your expectations.